The present invention relates to packaging and is particularly concerned with the packaging of a beverage containing gas in solution whereby on dispensing of the beverage for consumption, gas is liberated from solution in the beverage to develop a froth.
Sealed beverage packages that provide the aforementioned characteristics are known where the beverage is accommodated in a primary chamber of a sealed container having a secondary chamber containing gas under pressure and in which the secondary chamber communicates with the beverage in the primary chamber through a restricted aperture. Upon opening of such a known package for beverage dispensing, a pressure differential is developed which causes gas and/or liquid under pressure in the secondary chamber to be ejected by way of the restricted orifice. This ejection of the gas and/or liquid into the beverage in the primary chamber causes, or assists in, the formation of a head of froth on the beverage by the evolution of gas that is dissolved in it. Beverage packages having these froth developing characteristics have become well established in the art and commercially successful where the secondary chamber is provided by a hollow insert in the primary chamber (as disclosed in our British patent specifications 2183592A, 2256628A and 2260315A).
Our aforementioned specification 2183592A refers to a beverage package in which the hollow insert floats on the beverage in the primary chamber and such an arrangement has also met with commercial success in the embodiment envisaged by the disclosure in our European Patent Application No EP-A-0854089. With hollow inserts of the kind which float freely on the beverage in the secondary chamber there is a need to ensure that when the beverage package is opened (to cause the pressure differential to develop which results in gas and/or liquid being ejected from the secondary chamber into the primary chamber), the restricted orifice is submerged in the beverage of the primary chamber. If the package is opened whilst the restricted aperture is directed into the head space in the primary chamber it will be appreciated that the gas and/or liquid may be ejected from the secondary chamber without providing the required froth forming characteristics. To alleviate this latter possibility, floating inserts are usually ballasted in a sense to locate the restricted aperture submerged. However, experience indicates that even with ballasted floating inserts there are occasions where the insert floats into a condition when its restricted aperture is directed into the head space of the primary chamber. It is an object of the present invention to provide a beverage package which alleviates the latter possibility, especially where the container is a bottle. It is also an object of the present invention to provide a beverage packaging method and beverage packaging apparatus with improved and advantageous characteristics for manufacturing bottled beverages having floating inserts of the kind which the present invention relates.